This chapter identifies the best way of practicing psychotherapy. Faced with a large number of psychotherapy schools, it is tempting to think that the field is even more confused and unsatisfactory than drug therapy. In response, researchers have turned to randomized controlled trials in the hope of finding out which methods of psychological treatment are the most effective. The chapter considers whether psychological therapies can really be evaluated using the placebo-controlled double-blind methods, which have become the standard when measuring drug effectiveness. It is important at this early stage that enthusiasts for psychotherapy do not make inflated claims about what can be achieved with specific psychological techniques. Yet, there is evidence that bad relationships predict poor outcomes; while good relationships are a universal therapeutic good, and may yet turn out to be the single most important ingredient of effective psychiatric care.